SAN MARCOS  The San Marcos City Council on Tuesday is expected to vote on a new five-year contract with the county Sheriff’s Department, a deal that would increase the city’s cost for law enforcement though not provide any additional services.

In the first year of the proposed deal, the city would pay $14.55 million in operations costs, including patrol, traffic, financial crimes, homicide, juvenile intervention and services, an amount that’s up about 1 percent from the $14.38 million budgeted the year before.

The city’s operations cost would rise 2.75 percent to $15.24 million in its second year; 3 percent in its third and fourth years to $15.70 million and $16.17 million, respectively; and 3.25 percent to $16.69 million its fifth year, according to a city report.

Those costs do not include city’s share of Sheriff’s Department retirement costs, which would add another 2.8 percent to 4 percent to each year’s overall law enforcement cost, according to the report.

San Marcos Mayor Jim Desmond said the increases “are reasonable” given that the city has been “very happy with the Sheriff’s Department.” He noted that the city’s law enforcement costs have remained about the same the past couple of years.

By contracting with the county agency, San Marcos avoids high and unexpected liability costs, Desmond said. Cities with their own police forces are exposed to lawsuits involving accusations against officers.

The mayor added that there had been no discussions in recent memory about the city starting its own police force.

San Marcos city officials have recommended the City Council approve the new contract.

The city’s previous five-year deal with the Sheriff’s Department expired in June 2012.

Officials in cities that contract with the department, including San Marcos, Vista, Poway, Encinitas, Del Mar and Imperial Beach, negotiated jointly with the agency from October 2011 to December 2012 on terms for new deals.